Field of the Invention
Generally, the present disclosure relates to the manufacture of sophisticated semiconductor devices, and, more specifically, to various methods, structures, and systems for preparing MOL interconnects without titanium liners in semiconductor devices.
Description of the Related Art
The manufacture of semiconductor devices requires a number of discrete process steps to create a packaged semiconductor device from raw semiconductor material. The various processes, from the initial growth of the semiconductor material, the slicing of the semiconductor crystal into individual wafers, the fabrication stages (etching, doping, ion implanting, or the like), to the packaging and final testing of the completed device, are so different from one another and specialized that the processes may be performed in different manufacturing locations that contain different control schemes.
Generally, a set of processing steps is performed on a group of semiconductor wafers, sometimes referred to as a lot, using semiconductor-manufacturing tools, such as exposure tool or a stepper. As an example, an etch process may be performed on the semiconductor wafers to shape objects on the semiconductor wafer, such as polysilicon lines, each of which may function as a gate electrode for a transistor. As another example, a plurality of metal lines, e.g., aluminum or copper, may be formed that serve as conductive lines that connect one conductive region on the semiconductor wafer to another. In this manner, integrated circuit chips may be fabricated.
Known for fabricating today's semiconductor devices are layers of elemental titanium disposed on a first metal component. As shown in FIG. 1 (prior art), upon deposition of a barrier material 162 and a second metal component 160 on the titanium layer, the titanium layer undergoes oxygen gettering, forming titanium oxide 152.
Unfortunately, the presence of titanium oxide 152 between the first metal component 150 and the second metal component 160 leads to a number of undesirable outcomes. For one, titanium oxide 152 increases the contact resistance to the first metal component 150/titanium oxide 152/second metal component 160 structure. For another, oxygen gettering of titanium leads to the formation of voids 166 in the second metal component 160 due to the overhang of the titanium metal. Both these outcomes impair performance of semiconductor device 100.
Therefore, it would be desirable to have a process for forming a semiconductor device comprising a first metal component and a second metal component with lower resistance and reduced void formation, relative to prior art devices, such as that shown in FIG. 1.
The present disclosure may address and/or at least reduce one or more of the problems identified above regarding the prior art and/or provide one or more of the desirable features listed above.